


Batgirl: Mission Impossible

by cassacain



Category: Aquaman (2018), Aquaman (Comics), Batgirl (Comics)
Genre: Action, Adventure, Fighting, batgirl is like a spy haha, think mission impossible
Language: English
Status: Completed
Published: 2018-07-27
Updated: 2018-07-27
Packaged: 2019-06-17 07:37:08
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,396
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15456453
Author URL: https://archiveofourown.org/users/cassacain/pseuds/cassacain
Summary: Batgirl, Cassandra Cain, has been tasked with what should be an easy mission: recover the Atlantean royal goblet that was stolen by Amanda Waller and return it to its rightful owner, Aquaman. However, her mission grows increasingly dangerous as Black Manta unexpectedly appears and races Cassandra for the goblet.





	Batgirl: Mission Impossible

**Author's Note:**

> Warning for a racial slur against Asian people that appears fairly early in the story, as well as some sexism directed towards Cassandra, and, of course, violence.

Cassandra realized she was completely screwed about five minutes into the mission.

It was supposed to be a simple one. She disguised herself as an agent in Waller’s operation, and she waited until she had an opportunity to steal back an important Atlantean treasure. It was a goblet crafted with sacred gold and studded with glistening, luminescent pearls, and it was symbolic of royalty. When Orm was defeated and arrested, once again, he’d had possession of the goblet and it had fallen into Waller’s hands.

As a favor to Aquaman, Batman sent Batgirl to go recover.

She planned to wait until a quiet moment and then use her full arsenal of tools to steal the object back, and her accompanying fighting skills to make her way back through Waller’s agents and escape.

So, for the time being she hung around a hallway away from the primary entrance of Waller’s little seaside base, though she had entered through a backdoor. She was stationed here, but shifts rotated frequently so she just had to wait until she was placed closer to the goblet.

Only, that wouldn’t happen. Cassandra heard an explosion down the hallway, and like a sneaky tidal wave, chaos washed over her in one swift moment. There was a cacophony of voices bursting over her radio, shouting warnings and instructions. Apparently, a large number of men were invading the facility. Cassandra grabbed her taser, prepared to fight, but unwilling to give herself away. She waited until she saw two men dressed in black round the corner, guns out and firing.

Cassandra dodged quickly, prepared to rush down the hallway until she noticed her partner. His gun was out, but his hands were trembling, blue eyes rampant with fear. She sighed, forgetting her larger mission to run back and shove him down, narrowly avoiding a gunshot.

They lie together on the floor as the invading men surrounded them, aiming guns at them.   
“Did you see that? That tiny girl tackled him, avoided a bullet.” One of the men laughed. “Wouldn’t believe it if I hadn’t saw it. The little chink—“

“Now, now, boys,” the thundering, deep voice came from down the hallway. Cassandra watched as a man in a skintight black suit lumbered up, his helmet tucked beneath his arm. He was a dark-skinned black man with long eyelashes and warm brown eyes, but Cassandra knew the warmth was misleading.

Black Manta. She listened as he continued, saying, “I would watch the racial slurs, or else this might happen.” Before she could blink he’d whipped a blade out and thrown it through the offending man’s face. Cassandra couldn’t breathe as she watched the man stumble backward, breathing unevenly and collapsing to the floor.

The sight of death, as always, made the first two fingers of her right hand feel warm with blood, as though she’d just plunged them through that man’s throat. She looked down, finding her hand to clean, but she still squeezed her eyes shut before looking back up to level Black Manta with a glare.

She hadn’t expected him to be looking right back at her, and with a smile.

“Looks like we’re even then, girl. Tie these two up and shoot them if they cause any trouble at all.” Black Manta strode off without making sure the order was carried out, but with guns aimed at point blank range it looked as though Cassandra wasn’t going anywhere. She glared after Black Manta, sure that he wasn’t here for the government weapons or the few experimental subjects, but for Aquaman’s goblet. Why he would want a sacred Atlantean treasure she didn’t know, but considering he was a supervillain she could guess that the reason was either petty or spiteful.

Cassandra watched as he passed, and at least thirty men followed. He had a lot of manpower, all carrying blasters with them. One of his men carefully pulled the blade out of the fallen man’s head, cleaning it and rushing towards Black Manta with it. They disappeared through a door down the hall.

If Cassandra was going to recover the goblet she had to move fast. As soon as the door shut, she looked up at the door guards leering down at her and her partner. Her partner shook still, trying to share a fearful glance with Cassandra.

“You saved my life…thank you.” He said in a dull whisper, peering at Cassandra through his messy, dirty blonde mop of hair.

She smiled, “It was nothing.” She replied.

“Hey, stop the chatter you two,” one of Manta’s men said, edging his gun closer so it ran through Cassandra’s chin-length, chestnut-brown wig. He had one of those burly mustaches Dick Grayson said either made you a bodybuilder or a creep. “Now listen here, Manta said we can kill you if either of you gives us any trouble, and we noticed this girl here is quite the looker. Before we tie you two up, how’s about we see a lil more of her?”

“Stand up.” Said the other guard, a greasy man who gestured upwards with the tip of his gun. Cassandra eyed them both, getting ready to stand. Her partner grabbed her arm.  
“Wait, they can’t make you do anything—“

“Shut up!” The creep yelled.

Cassandra shot her partner a smile. “It’s fine, don’t worry about it.” She said, her voice perfectly calm. She got to her feet, and the men lowered their guns, putting them in their holsters and putting their hands on their hips as they looked her up and down. They leered confidently, and Cassandra smiled.

They’d just made her life a lot easier. The lucky thing about the uniform was that it was all-black, with a chunky green vest she could stuff a jillion of her Batgirl supplies into. She stood for a second, looking between them and batting her eyes.

One of her hands roamed up her vest, reaching under it. The greasy guy inhaled deeply. She whipped out a batarang, hitting him squarely in the head. Then she lurched forward, going for creepy mustache guy. She grabbed his arm, breaking it brutally in two spots, before throwing him like a sack of potatoes into his greasy friend. She leaped at them, jabbing pressure points on them both and knocking them out.

She turned to her partner with a smile, pulling out from her uniform vest a black ski mask. She pulled it on over her head, aligning it so she could peer out at him.

“You…you’re not just a guard, are you?” He asked. Cassandra grinned.

“Take one of their uniforms and head back out that way. If anyone tries to stop you tell them Black Manta has a priority mission for you. There’s a set of jeeps outside, owned by Waller. The keys she gives all of us are budgeted and will work on any of them. Good luck.” As she spoke, she put on the adhesive gloves Batman had designed especially for this mission. They made wall climbing easy, so she didn’t need her grappling gun.

Then Cassandra launched herself into a jump, pulling the cover off the ventilation shaft. She snaked in, maneuvering to put the cover back on, before bringing her wrist closer to her face. She clicked her watch on, looking over the 3D map Tim and Babs had set up for her before she set off on the mission.

If she followed this vent down straight, hooked an early right, and took two back to back lefts two four down, she should be able to come out ahead of Black Manta. She set to it, doing the sprint version of a crawl through the vent. The vents were dusty but they were wide enough, and she made it quickly.

She reached the end of her journey and sat directly over a vent cover. She could see a patch of the white floor below her, and it looked clear, but it was just a sliver of the room. She pressed her ear to the bottom of the vent and listened for a long moment. Hearing nothing, she knocked the cover lose. It clattered to the ground, the loudest noise she’d made since taking those two men out, and then she leaped through.

In front of her, the room was clear. She let out a breath. Her back prickled with the feeling of someone behind her, and she turned to see Black Manta standing across from her with a dangerous smile. His men were heaped behind him and around him, and for a long second her heart beat in erratic panic.  
Then she saw the glass wall separating them. On it was a frisbee-shaped device made for cracking bulletproof glass, which could then be kicked through once it was splintered. There was a countdown of thirty seconds on it.

“I wondered what had happened when my men radioed me and said that the two guards had escaped, and my men were knocked out. I assumed you both left by jeep, and my men had somehow overlooked the asian girl. I suppose you’re undercover, but you aren’t Waller’s.”

Cassandra bit her lip, glancing at the countdown. Fifteen seconds.

“If it’s the goblet you want, you won’t have it. It will be mine.” Black Manta promised, an edge of danger to his words.

She no longer cared to listen. Turning with a start, she sprinted faster than she ever had down the hall, opening the adjacent door with her keycard and flying through, slamming it behind her.

Despite that, she still heard the snap of the machine finally going off, sending mammoth cracks lacing up the glass like fat snakes. She had no time left. She ran in a panic, only able to picture the X on the map where the goblet was kept. She ran through two rooms before reaching the correct one, where she found the reason for the glass wall, which only appeared in lockdown.

This particular facility was owned by Waller but ran by a close personal friend, Jackie Blake. Jackie’s son was appointed as her right-hand man.

Cassandra recognized his face from the briefing before her mission. She rushed over to where he was curled, crying and shaking and clutching the goblet to his chest in the corner of the room.

“Let me take the goblet. They’ll kill you if you keep it.” Cassandra said, outstretching her hand.

Blake glanced at her hand, then at the goblet. Greed shone in his eyes, but the sound of approaching footsteps sobered him up. He practically threw the goblet at her, and she caught it easily.

It was too chunky to hide in her vest, so she threw the mandatory twin guns out of her fat, backpack-like thigh holster and crammed it in instead. She jumped up on the wall, yanking the vent cover off just as Black Manta entered the room.

“Shoot to kill!” He yelled, but she’d already disappeared into the vent. She heard him scream, “There’s only so many places she can come out of there. Go, station yourselves!” He sounded unbelievably angry, and his voice betrayed his bloodlust.

He’d come close to the goblet and just missed it. However, if she didn’t stay on her A-game, his men had a good chance of figuring out where she meant to leave the vents.

But his men could only move so fast. Cassandra had a crisp image of the facility’s layout in her mind, and if she moved fast enough she could reintegrate into Jackie Blake’s guard force and wait for Black Manta to gather his men at the front entrance. She could slip out the back entrance easily after that, once Manta’s patience wore slim enough that he got sloppy.

In the meantime, she reached the cleaning closet adjoined to Jackie Blake’s office. She couldn’t enter the office itself, because that ventilation shaft was connected to an entirely separate set of vents. But, if she could get from the cleaning closet into the office, she had a good chance of making it to the back exit of the facility.

She peered through the vent into the cleaning closet and examined it through the vent for anyone within. There was no one, so she exited the vent calmly, pulling her ski mask off. She took the brown wig and crammed it to the bottom of a trash can on a cleaning cart, before reaching into her vest and pulling out a bright blonde one instead. This one was a pixie cut. She tapped her facial distorting mask, switching her asian face for white features. She picked a face with freckles, hoping that would be different enough.

Checking her appearance in a compact, she decided she’d pass. The facial distortion tech, invented in a team-up between Alfred and Tim, was incredible, but it had limits. It couldn’t change her eye shape and facial structure, and her face’s skin color had to match her neck, so if one was attentive and looked closely enough…well, it wouldn’t be fantastic for her.

But she doubted any of Black Manta’s idiot henchmen would notice, and if she could avoid the attention of Manta himself she was in the clear. She listened at the door before opening up and casually entering Jackie Blake’s office. It was a wide office, crammed with three other guards and Jackie Blake herself.

“What? Were you in there the whole damn time?” Jackie Blake demanded, standing and glaring at Cassandra angrily. Cassandra bowed her head.

“I’m sorry…I heard what was happening and was afraid…” Cassandra lied. Jackie Blake put her hands on her hips and scowled.

“Our base is under attack, our communication system is completely cut off, and this office is locked from the outside. I have at least five enemy guards patrolling out there, and you think now’s the time to—“

Jackie Blake was cut off when the door was thrown open.

Black Manta stood, helmet under his arm as he glared at Jackie Blake and her four guards. Cassandra could feel the volcanic edge of his fury just by the tenseness of his broad shoulders, the subtle clench of his fists.

He stormed in, gaze focused on Jackie Blake and blazing. “I want answers, Blake. There’s a rogue element in this building, and they’ve taken the goblet. What do you know?”

Jackie Blake cowered for a moment before she smiled. “Someone’s saved the goblet, huh? That would be my son, his one job is to secure the goblet. You’ve been outdone, Black Manta.“

As soon she finished her sentence, Black Manta lifted his helmet up, lowering it onto his head. Cassandra realized what he intended a moment before he blasted through Jackie Blake with lasers from his helmet. Cassandra gasped, watching as Jackie Blake’s chest was momentarily replaced with red light, before becoming just an empty hole.  
She drifted to the floor like a paper doll, her expression stunned.

Cassandra fell to the ground alongside her, squatting and checking for any signs of life. She already knew there would be none, but she lingered over Jackie, horrified by what was done to her.

“It couldn’t be your son, Jackie Blake, he was pissing himself in the room where the goblet should have been. You should be pleased to know you’ll see him rather soon, in the afterlife, of course.”

Cassandra’s chest ached, and she regretted leaving the Blake boy behind. She hadn’t realized that they would kill him; the regret felt as potent as a jaw-shattering blow from Bane.

She was responsible for two deaths, through her own carelessness. Gritting her teeth, she decided she would lash back at Black Manta in the only way she knew: she would ace this mission.

She looked up to find Black Manta speaking to all his men, both in the room and over his comms.

“Nobody comes in or out of this room. I want every guard detained and brought to me. The person causing all this bullshit is ridiculously short, so if they’re over, say, 5’6 just shoot them in the knee or leave them tied. Or kill them, I don’t really give a shit anymore. And if they’re asian, you better bring them to me now.”

Black Manta practically threw his radio down once he was done with it. He turned to the five guards, glaring at them each in turn. As he’d been talking, his men had jostled them in an even line. Cassandra stood nervously at the beginning of it.

“Today’s your lucky day. Every one of you idiots is shorter than a yardstick, and I need the goblet thief alive.” Black Manta snarled. He paced back and forth in front of the line, examining them all through his helmet.

Cassandra felt hot sweat pour down her neck as he looked at the other four agents up and down with narrowed eyes. Her heart beat frantically, and she hoped her disguise was enough.

Black Manta stopped in front of her. He was as still as a tiger, perched on a rock above her and examining her for any weakness. One wrong, provoking move, and she’d end up with a hole in her chest, just like Jackie Blake and, presumably, her son.

“Step forward.” Black Manta ordered, an angry bite to his tone. Cassandra obeyed immediately, betraying none of her anxiety in her body language. She kept her chin up as Black Manta carefully examined her.

“Grab her. She’s the one.” Black Manta said, and she could hear his grin in his voice. The two henchmen that stood behind her lunged for her at once, but she grabbed their arms, backflipping in the air and hitting the wall. Her adhesive gloves stuck at once.

“Do not shoot to kill!” Black Manta yelled. Cassandra scurried inhumanly fast across the wall, reaching the vent cover and yanking it off. In the second she was still, a blasting pain ran through her side. She cried out, but forced her way through it, dashing into the vent and rushing through it like a frenzied animal.

The pain wasn’t from a bullet. It was a blade. Glancing at her side, she saw, sure enough, Black Manta’s personal weapon sticking out of her side. To keep the bleeding to a minimum, she decided to leave the weapon in, painful as it was. 

On top of her injury, Cassandra had another problem. Overwhelmed by pain and adrenaline-boosted panic, Cassandra had lost the clear image of the map. She paused for a moment to open the map Tim had installed in her watch until she heard a banging in the vent behind her.

She also heard Black Manta yelling, and in a blind panic she picked a random direction and headed that way. She knew this situation was the opposite of good, but she hadn’t expected Black Manta to see through her disguise and throw her into this mess. She was heading down a vent in the wrong direction, the occasional drop of blood leaking out of her side and leaving a trail if someone had good enough vision to follow it in this dim lighting.

She was dead if he caught her. White hot panic made her travel faster than before until she reached a place where the vent opened up. There was a fan visible through a grated cover, and beside that fan was a control panel.

It didn’t take a rocket scientist to figure the control panel out. Open, shut. She pulled the lever, her side screaming in protest, and the vent shut behind her.

She let out a little laugh of relief. She was far from in the clear, but at least there was a layer of metal between her and Black Manta, and his men were big enough that they would have to back out of the vent shaft, they couldn’t just turn around.

Cassandra continued forward, crawling to the edge of the opening with the fan and pulling up her map. Sure enough, she’d snaked off onto the wrong path, but if she went through a large test subject room she could make it to the back exit fast.

It was worth a shot, she figured. Better than Black Manta getting his murderous hands on both her and the stupid goblet. Having picked her new route, Cassandra slipped through the tunnels until she reached the vent she had to exit. From here, the ventilation shaft would branch off and head back towards the entrance, and there was a third shaft that covered the exit in the back of the facility.

She just needed to drop into this text subject’s room. She looked down to see the room bathed in an eerie red light. The floor was extremely distant and seemed to move. It was dark and murky, and Cassandra realized suddenly that it was water. She frowned but decided not to think too much of it. There was a metal walkway she could drop down on.

Yanking her ski mask back over her head, Cassandra kicking the cover off the vent. The water stirred as she threw herself down, landing on the walkway with a light thud. She looked to either side of the room but saw no guards. She peered over the walkway into the murky water, before her hand rushed to her bloody side.

The landing had jostled her injury some, and a bit more blood had escaped. She wondered if she would need to take the knife out and apply the healing putty Barbara had given her. It was effective for closing injuries one obtained on the field.

She figured she would do that once she was out of this creepy test subject room. After all, who knew what was in the water. Slinking along the metal walkway, quiet so as not to disturb whatever it was she shared the room with, Cassandra soon got a partial answer.

Bathed in red light, fleshy tentacles began to snake their way out of the water. Dotted with teeth, they were the thick sort of tentacle that could take down a boat, and, now that Cassandra considered it, this room was unusually long. It nearly bridged the gap between the back exit of the building and the center of it, making this room as long as a cruise ship.

She suddenly understood what, exactly, this room hosted, and as more tentacles burst out of the water she realized that the thing lurking beneath her smelled her blood.

Sprinting openly, Cassandra rushed to the door. She leaped when a tentacle snaked over the side of the walkway, grabbing onto the railing when it yanked the walkway downward, causing a large dent. Another powerful pull and the walkway gave out; Cassandra bit back a scream as she dangled. She had to climb her way up, but with the tentacles snaking the walls, searching for her, she needed a way to divert this Kraken-squid-thing’s attention.

Using one hand to dangle from the railing, she tore the knife from her side. She swallowed a howl of pain instead of rearing back and hurling the knife to the opposite end of the room. Suddenly, the tentacles were distracted and confused.

Cassandra used her opportunity to quickly and stealthily climb the broken walkway, reaching the door and using her keycard as quickly as she could. She threw herself out, the door sliding automatically shut behind her, and fell to her knees.

She was drenched in sweat, and the wound on her side demanded her attention. She reached into her vest pocket, grabbing bandages and healing putty. She hiked her shirt up, wiping the front end of her injury clean and shutting it with putty. She did the same for her back and disposed of the bloody bandages in a trashcan.

Cassandra was deeply shaken, but she survived. Now, it was a race to the back exit, which was a hallway away. And if there was one thing this entire mission had prepared her for, it was a good sprint. She took off running, forgetting her injury, and bolted towards a guard. He aimed his gun, and she easily dodged the bullet, hurtling into him and introducing her knee to his face. She similarly disarmed and knocked out the next guard, moving through them.

The exit was inside. It looked to her like the Holy Grail had to Indiana Jones.

She was one keycard scan away from escaping Black Manta.

There had never been a more satisfying beep of access from a machine. She pushed the door open, the sun hitting her ski mask and uniform, but still managing to feel refreshing.

She wasn’t out of the clear yet, though. Running down the hallway, one of the men closest to the back exit had been radioing Black Manta. He was on his way. She threw herself down the stairs leading over piled rocks and towards a short dock, where several small ships sat. One of them was hers, and as she sprinted down the deck and hopped into it she glanced back up at the facility.

Nothing, yet. She untied it quickly, pulling the rope back into the boat and hurrying to start it. She heard shouts and turned to see several henchmen rush out, flanked by Black Manta.

“None of you idiots shoot! You’re all lousy shots!” Black Manta commanded.

The boat started and took off, a straight white line through the crystal-blue water. That white line was followed quickly by Black Manta’s laser.

Smiling, Cassandra smacked a button on the boat’s dash, and the tiny boat transitioned quickly, morphing into a one-person mini jet, and taking off into the sky.

Cassandra flew off as quickly as possible, waving sassily out the back window of her jet in the second before she hit the stealth button and it turned invisible.

Below, Black Manta let out a stream of impotent curse words, so irate he was practically stomping his foot. Too little, too late.

A week later, Batgirl proudly attended a Justice League meeting alongside Batman, and, with a smug smile, she presented the bejeweled goblet she’d rescued out from under not only Amanda Waller (well, her assistant Jackie Blake, but still), but Black Manta himself. 

Lois Lane herself snapped the now-viral photo of Batgirl shaking Aquaman’s hand and holding the goblet up for the camera.

Black Manta printed that particular photo out for use as target practice.

**Author's Note:**

> There is a sad lack of good, action-packed Black Manta content. Similarly, there can never be too much Cassandra Cain content, so I thought it might be fun to pit them against each other! This was a lot of fun to write so hopefully it will be as much fun to read. I went for Young Justice vibes, in celebration of its impending release. Anyway, I hope you loved it, and thanks for the read!


End file.
